DSL Health in Menlo Oaks

Over the last several months, I have been corresponding with several neighbors in Menlo Oaks about their DSL service. Several
have commented on their slow service. It is true, with DSL the farther you are from the phone company the slower or non existent
the service becomes. We are all relatively
the same distance from the central office (in Palo Alto). My service has been running for 5 years and I have found a few things that might explain some of the discrepancies.

To check the health of your service (DSL or otherwise), open up a web browser and search for “DSL Speed Test”. You should see numerous links to choose from. Some sites require your computer to run a java client. If you don’t have one installed or don’t know what that is, the test won’t work. Once you have the test up and running, it will take a minute or two. What you should see when the test completes is a result page showing the speed results for downstream and upstream
data rates. Downstream describes the data being delivered to your house, upstream
is the opposite direction.

If you selected a test server in a far away city you’ll be testing more of their network instead of the one in your house.

On average, the numbers from the test usually don’t change much but if they do, then this could be a clue that something is wrong or you are on a Cable modem which operates on a totally different system. In the case with DSL, if your results are always slow then it is time to roll up the sleeves and go to work.

My test data indicated my downstream was nearly 1.2Mb/s (mega bits per second) and 316kb/s upstream (kilo bits per second) of which they only guarantee the upstream rate of 256kb/s in my case. If your DSL service
doesn’t run within twenty percent of those rates then most likely the link is not operating properly.

Since all of our homes are the same distance
from the central office (or CO for short) we should all expect to get roughly the same numbers. When my DSL connection
was first installed, it too wasn’t nearly as fast as it is today. I found the solution to the speed problem buried in the technology.
By simply moving some devices and changing a few wires, I was able to go from 300kb/s downstream to the speed I am clocking today.

How it all started…

The crew that came out to install the DSL service was desperately trying to get in and get out as fast as possible. The very second
they saw green lights and could ping a web site, they packed up their truck and left. This is standard operating practice as they are trying to perform as many installs as possible in a day. When the contractors came to install the service, they asked me where my computer would be and placed the equipment next to my computer.

When the phone company installed the service
at our house they added a “splitter box” and put it next to the DSL modem where the phone was previously. The splitter box was connected into an existing phone jack and splits the line into two circuits, one for data and the other for voice. The phone is reconnected to the voice side and the DSL modem is connected to the data side. The other side of the DSL modem is connected to a firewall and eventually into my computer.

What the installers don’t tell you is that long wires are notorious for attenuating high frequency energy like high speed data. In other words, the farther down the wire the energy travels, the weaker the signal becomes. This effect makes it harder for modems to recover the energy the farther it is from the CO and why some people can’t get DSL. To receive the best possible service,
the DSL modem must be able to get as much signal from the CO as possible. What I discovered was a huge improvement when I moved the splitter as close as possible to the box where the wires from the phone company terminate.

Discovering High Speed

The crucial element for improving or maintaining the quality of the DSL carrier I discovered is to move the equipment as close as possible to the phone box. The next best technique is to put the DSL modem on a dedicated connection to the splitter box. The important concept is to intercept as much of the high frequency energy (your data) as soon as possible and not let any of it get into other wires feeding extension phones in the house. By keeping the modem
connection to the splitter as short as possible and putting the splitter as close to the outside box as possible, more of the DSL energy can be preserved. The voice connection doesn’t care where the splitter box is placed because those signals aren’t affected by longer wires.

Most DSL modems are not rated for outdoor
use, but the splitter box was. Since the Ethernet signal can travel over 1000 feet using CAT5 cable, the DSL modem can be placed in an out of the way location but somewhere near a power outlet.

My splitter box is now inches away from the phone company box. I used a foot of twisted
pair wire to connect between the phone box and the splitter box. The DSL modem is only 3 feet from the splitter. After making
those few changes my link has never been slower than 1.1Mb/s. I also connected the power supply to a small UPS to protect the equipment since it deserves as much protection as the computer you would use with it. Since then, my network has never failed with only a few DNS server problems which are out of my control.